Latch mechanism



May 27, 1941. s. B. WHITTIER LATCH MECHANISM '2 Sheets-Sheet 1 Filed Nov. 26, 1938 May 27, 1941.

s. B. WHlTTlER LATCH MECHANISM 2 Sheets-Sheet 2 Filed NOV. 26, 1938 Patented May 27, 1941 LATCH -MEGHANISM Sidney B. Whittier, Barnstable, Mass. Application November 26, 1938, Serial No. 242,452

Claims.

This invention relates to improvements in latch mechanism for automobile doors and more particularly to latch mechanism which may be operated by an external handle or an internal handle, the internal handle being also operable to secure the bolt in projected position.

It is an object of the invention to provide a latch mechanism of the kind described which is contained in a relatively fiat housing offset from the axis of the bolt so as not to interfere with the sheet of glass which is used as a window for an automobile door and which is mounted to be lowered into the body of the door from the window opening.

Another object of the invention is to provide latching mechanism which is easy to open and easy to shut, so that slamming is unnecessary and muscular effort of the operator is reduced to a minimum.

It is a further object of the invention to provide a latch mechanism in which the bolt is positively held in its retracted position and in its projected position until released by suitable means.

It is a further object of the invention to provide a bolt with a conical or tapering end fitting into a lined socket in the door jamb and positively held therein while the door is shut so as to prevent relative working between the door and the door frame.

Other advantageous features will be apparent to one skilled in the art from the description of certain embodiments of the invention which follows and from the drawings of which- I Figure 1 is a perspective view of a fragmentary portion of an automobile including a door in which is mounted mechanism embodying the invention.

Figure 2 is a side elevation of a latching mechanism, the side plate of the housing being omitted to show the working parts.

' Figure 3 is a view similar to Figure 2 but showing a portion of the door jamb and showing the working parts in dilferent positions of operation.

Figure 4 is similar to Figure 2 but showing some of the parts in diiferent positions of operation.

Figure 5 is a section on the line 5-5 of Figure 3.

Figure 6 is a section on the line 6-45 of Figure 3.

Figure 7 is a fragmentary elevation similar to Figure 2 but showing the parts in different positions of operation.

Figure 8 is a side elevation of a modified form of the invention.

Figure 9 is a section on the line 99 of Figure 8.

Figure 10 is a section on the line Iii-ill of Figure 8.

Figure 11 is a section on the line ure 8.

Figure 12 is a side elevation of another modified form of the invention.

Figure 13 is a section on the line I3l3 of Figure 12.

Figure 14 is a section on the line hi -l4 of Figure 12.

Referring to the drawings, Figure 1 is a fragmentary view of an automobile body including a door 20 having a latching mechanism 22 mounted therein with an exterior handle 24 and an interior handle 26. The latching mechanism, as indicated in Figure 2, includes a bolt 3!) which is H-H of Fighorizontally slidable in the casing of the lock andis provided with a tapering head 32 adapted to project through an opening 34 in the edge of the door into a socket 36 in the door jamb 38. As shown in Figure 3, the socket 36 is preferably lined as at 40 with a rubber lining, the bolt head 32 fitting snugly in the lining 40. The tapering extremity of the bolt head 32 may be frusto-conical, as shown, or may be conical or rounded as desired, but in any event the tapered end portion is preferably followed by a cylindrical portion 42 which merges into the vconically tapered portion and fits snugly into a cylindrical portion of the socket 36. In order to make room for the window glass carried by the door, the bolt head 32 is relatively short, the shank portion of the bolt being shown as a pair of plates 44 and 46 which are secured to each other face to face, both plates being secured to the bolt head 39. The tWo plates 44 and 48 and the bolt head 38 may all be cast as an integral unit if preferred, the plates 44 and 46 being laterally offset from the axis of the bolt head so as to slide between the side walls 50 and 52 which, with the front wall 54, form a housing having a thickness less than half the Width of the front Wall.

The operating mechanism is located in said housing and comprises a tumbler 56 in the form of a bell-crank which is preferably madeof plate of the same thickness as the, plate 44. This tumbler is pivotally mounted on the bolt. 'To this end, itmay be provided with a circular portion 58 which fits in a socket 611 formed by a circu lar recess in a side edge of the plate 44. This tumbler alsoincludes an arm 62 the end of which engages a shoulder 64 on a stationary plate 66. The tumbler 56 also has an upright arm 10 which is engageable by an arm 12 of a roll-back I4 which is mounted on a squared rockshaft 16 to which the outer door handle 24 is secured. When the rockshaft 16 is rocked in a counterclockwise direction, as shown in Figures 2 and 3, the arm I2 bears against the arm I8 and rocks the tumbler 56 so that the arm 82 moves clear of the shoulder 64, whereupon the bolt is free to be retracted. Further movement of the arm 12 pushes the tumbler 56 toward the right, this resulting in retractive movement of the bolt owing to the engagement of the portion 58 of the tumbler 56 in the circular socket 88. This movement of the tumbler 56 and the bolt is against the pressure of a spring I5 which bears against the arm I8. This spring tends to project the bolt toward the left but need not be particularly strong since the bolt is normally locked in its projected position by the engagement of the arm 62 against the shoulder 64. Thus the spring 15 is relieved of the function oi. holding the bolt in projected position. A spring I8 bears against a finger 88 on the rollback 'I4 so as to tend to rotate the shaft I6 in a clockwise direction to the normal position of the shaft shown in Figure 3.

The bolt 38 may also be operated by manipulation of the interior handle 26. To this end, the handle is connected by a suitable bar 82 to a plate 84 which is slidable in the housing. This plate is provided with an elongated horizontal slot 86 to receive a lug 88 which is struck down from the arm I8 and projects into the slot 86 as indicated in Figure 5. For this purpose the plate 84 is mounted above and in a common plane with the plate 46. When the bolt is operated by the outer handle 24, the lug 88 travels idly in the slot 86, the plate 84 remaining stationary. If the interior handle 26 is operated to retract the bolt, the left-hand end of the edge of the slot 86 engages the lug 88 as the plate 84 is moved toward the right. This rocks the tumbler 56 toward the right, as previously described, releasing and retracting the bolt 38. The interior handle 24 may be operated in the opposite direction to lock the bolt in such a manner as to render the outer handle 24 inoperative. For this purpose a nose 98 is provided on the left-hand end of the plate 84, this nose being movable into engagement with a shoulder 92 on the roll-back I4 when the plate 84 is moved to the left from the position shown in Figure 2 to the position shown in Figure '7. This locking movement of the plate 84 is against the resistance of a spring-pressed detent 94 which is engaged by a projection 98 on the upper edge of the plate 84. The detent 94 prevents movement of the plate 84 into its locking position unless positively moved to such position by operation of the interior handle 26. A suitable spring 96 is provided to press against a lug 98 on the plate 84 so as to press the plate 84 toward the left. This spring, however, is of insuflicient strength to move the plate to the looking position shown in Figure '7.

Another tumbler is provided to hold the bolt in its retracted position. This consists of a dog I88 which has a trigger portion I82 projecting through the end wall 54 of the casing. The tumbler is rockable to and from a position in which the inner end I83 of the dog engages a shoulder I84 on the plate 44. A lug I85 on the tumbler is seated in a slot in the wall 58 to act as a fulcrum for the tumbler. The dog I88 is yieldingly held in looking position by a suitable spring I86, as indicated in Figure 6. When the door is swung shut, the trigger element I82 engages a tripping device which may be a setscrew I88 adjustably mounted in the door jamb, the projecting end of this setscrew being in the path of the trigger member I82. This engagement rocks the dog I88 to the position shown in Figure 6, releasing the plate 44 so that the bolt 38 is free to move toward the left under the influence of the spring I5. The screw I88 is adjusted so that the bolt is released just as it reaches a position opposite the socket 36. The spring I5 thereupon moves the bolt toward the left so that the bolt head 38 enters the socket. The spring also rocks the lever member 56 so that the arm 62 engages the shoulder 64 and positively locks the bolt against retractive movement until the tumbler 56 has been rocked by the exterior or interior door handle. As shown in Figure 6, the cam face of the trigger element I82 which actually engages the tripping element I88 is approximately parallel to the plane of the adjacent edge of the door, especially when the trigger is in the tripped position shown in this figure. Thus, when the door swings shut, the trigger element wipes its cam face along the end of the screw I88 instead of bringing up solidly against the side of the screw I88. For this reason, the door can move past its normal closed position without bending or otherwise injuring the trigger I82 or any of the mechanism associated therewith. Hence it is not necessary that the inner edge of the door bear strongly against the usual rubber pad or buffer I89 which is mounted on the jamb, when the door is in its closed position. Ordinarily such a buffer serves both to cushion the impact of the door when it is slammed shut and also to press the shut door firmly against the latch to prevent rattling. For this reason, the buffer in the usual car must be compressed when the door is shut, necessitating a strong push or slam to shut the door. Since in the present invention the bolt 38 in the lined socket 36 serves to prevent rattling, it is not necessary for the door to press firmly against the buffer I89 when shut. On the contrary, the door may be slightly spaced from the buffer I89, when shut, or the buffer may be made of softer material than that customarily employed, so that the door can be shut by a gentle push instead of a slam. This is made possible by the form or the trigger which trips the latch when the bolt is opposite the socket 36, but which permits the door to move past its normal closed position without injury to the trigger or any other element of the mechanism.

Figures 8 .to 11 inclusive illustrate a modified form of the invention in which the bolt head 38 is secured to or integral with a fiat elongated shank II8 notched to receive a tumbler III which preferably has two or more shoulders H4 and H8 either of which is adapted to engage a lug I I8 on the stationary housing wall member I28 to lock the bolt in a projected position. If, when the door has been shut, the bolt fails to be projected to its fullest extent by the operating spring, the lug II8 may catch on the shoulder I I4. If, however, the bolt is projected to its extreme position, the end shoulder I I6 engages the lug H8 .to: lock the bolt in its fully projected position. A suitable spring I22 bears against a laterally projecting portion I24 of the member II2, causing this member to tend to assume its locking position as shown in Figure 10. Operating means for retracting the bolt are located in. the narrow housing defined by the wall I28 and a parallel wall I25 which is preferably integral with the end wall through which the bolt head projects. The thickness of the housing is less than half of the width of the end wall so as to provide space for the window glass in the door. The bolt head, however, preferably has a diameter nearly as great as the width of the end wall so as to have a large bearing surface in the socket in the door jamb which it enters. The operating means may include a lever arm I26 loosely mounted on a shaft I28, this lever arm having a curved edge portion I36 bearing against the projecting portion I24 of the tumbler II 2. The lever I 26 is provided with an ear I32 engaged by a lug I34 on a roll-back member I26 which is fixed on the shaft I28. A spring I 36 presses an arm I46 projecting from the roll-back I36, tending to turn the shaft I28 in clockwise direction, as shown in Figure 8, so as to hold the arm I46 resiliently against a stop pin I42. If the shaft I28 is rocked against the force of the spring I38, the lug I34 bears against the ear I32 so as to rock the arm I26. This presses against the projecting portion I24 of the tumbler II 2 so as to move the shoulder II6 clear of the lug IIS, thus releasing the bolt for retractive movement. Further movement of the arm I26 causes the bolt to be retracted with the tumbler II2 against the pressure of the spring I22 until the bolt is locked in its retracted position by another tumbler shown in Figure 9. This comprises a dog I44 which is provided with a lug I 66 seated in a slot in the casing to act as a fulcrum. The dog is rocked by a trigger element I46 which projects through an opening in the end wall of the casing so as to engage a setscrew or other tripping element mounted on the door jamb. The dog I44 has an inclined edge I56 which is adapted to engage an edge portion I52 of the lever arm I26 when the latter is rocked to move the bolt in its fully retracted position. The dog I44 is pressed toward its locking position by suitable means such as a spring I54. Thus, when the lever I26 is rocked so that it clears the dog I44, the latter moves into the same plane as the lever I26 and the edge I56 engages the edge portion I 52 to prevent reverse movement of the lever arm I 26 until the dog I44 is rocked in the opposite direction by engagement of its trigger I 46 with a tripping element on the door jamb.

The bolt 36 may be operated by an interior door handle which is connected to a sliding plate I66. This plate is provided with an ear I62 adapted to engage a corresponding ear I64 on the bolt 36 when the slide I66 is moved toward the right as in Figure 8. When the bolt is operated by rocking the shaft I28, the ear I64 simply moves away from the ear I62. The slide I66 can be moved toward the left from the position shown in Figure 8 so as to lock the bolt 36 in its projected position and to render the exterior door handle inoperative. To this end, the slide I66 is provided with an end edge portion I66 which is adapted to engage a lug I68 on the lever arm I26 when the slide I66 is moved toward the left from the position shown in Figure 8. As indicated in Figure 9, the lug I 66 is provided with a sloping cam surface on which the edge of the slide I 66 rides, the result being to push the upper portion of the lever arm I 26 laterally against the force of a light spring I69 so that the ear I32 is disengaged from the lug I34 on the rollback, as indicated in dotted lines in Figure 11. Since the arm I26 is loosely mounted on the circular shaft I26, manipulation of the handle attached to the shaft I28 thereupon has no effect on the lever arm I26. The slide I66 may be releasably retained in the position shown inFigure 8 or in its locking position by any suitable means such as a leaf spring I16 having an. end portion engaging in one or another of a pair of apertures or recesses I72 and I I4 in the slide I66. The slide I66 is pressed toward the left by a suitable spring I76 which bears against a lug I18 projecting from a side face of the slide, this spring being of insufiicient strength to move the slide to its locking position against the retentive force of the detent member I'I6.

To avoid looseness or rattling of the bolt when the door is closed, the forward portion I86 of the shank is relatively thick and is slotted, as indicated in Figure 11, near the upper and lower edges to form horizontal strips I82 and I84 which project rearwardly beyond the portion I86 of the shank. A pair of short flanges or rails I66 and I 86 projectin from the side wall I 26 fit in the slots, providing ample bearing surface for the sliding shank of the bolt. The free portions of the strips I62 and I64 converge slightly so that, when the bolt is projected, these converging portions bind somewhat on the rails I85 and I66 and thus prevent up and down looseness of the bolt. Sidewise looseness is prevented by the engagement of the leading end edge of the shank portion I86 of the bolt with the curved corner surface of the housing wall I25 at I86 (Figure 10). This wedges the bolt head sidewise against the opposite edge of the aperture when the bolt is fully projected.

Figures 12, 13 and 14 illustrate another form of the invention in which the bolt 36 is provided with a tumbler I96 which is pivoted to the bolt as at I62. One arm I64 of the tumbler I96 engaging a suitable shoulder I66 when the bolt is in projected position to lock the bolt positively against rotation, The other arm I98 projects upward and is pressed toward locking position by a suitable spring 266. The arm I98 is also engaged by an arm 262 projecting from a clutch member 264 which is slidable on a square rockshaft 266 but which is rockable thereby. Loosely mounted on the shaft 266 is a complementary clutch member 268 which is provided with an arm 2I6 connected through a suitable link 2I2 to the interior door handle of the automobile, the shaft 266 having the exterior door handle 24 mounted thereon. A suitable spring 2I4 presses the clutch members 264 and 268 into engagement. Rocking movement of the shaft 266 in a counter-clockwise direction, as shown in Figure 12, presses the arm 262 against the arm I98, rocking the member I96 so as to move the arm I64 clear from the shoulder I66. Further movement of the arm 262 pushes the bolt 36 to its retracted position against the pressure of the spring 266. Since the clutch members 264 and 268 are normally in engagement as indicated in Figure 14, the arm 262 may also be rocked by manipulation of the interior door handle. Operation of the interior door handle in the opposite direction, however, causes the inclined edges 2I6 of the clutch member 268 to ride upon the corresponding inclined edges 2I8 of the clutch member 264 causing the latter to shift along the shaft 266 against the spring 2I4 so that the arm 262 is moved out of connection with the arm I68, As 10ng as the clutch member 264 is held in this laterally shifted position, manipulation of the exterior door handle 24 does not operate the bolt 36.

When the bolt is in its fully retracted position, it is locked in such position by a tumbler 226 which rocks on a fulcrum 222, this tumbler having a trigger member 224 which projects from the edge of the door to engage a tripping element such as the setscrew I08 shown in Figure 3. The end 226 of the tumbler 22B engages the arm I98 when the bolt is in its fully retracted position, as indicated in Figure 13, preventing any movement of the bolt toward the left. When the trigger member 224 is pressed against the force of a spring 228 to rock the tumbler 220 so that its end moves clear of the arm I98, the bolt can then be projected by the spring 20!).

It is evident that various modifications and changes may be made in the embodiments of the invention herein shown and described without departing from the spirit or scope thereof as defined in the following claims.

I claim:

1. In a latching mechanism, a slidable bolt having a shank portion in the form of a flat plate with a circular notch in an edge thereof forming a socket, a tumbler slidable with said bolt, said tumbler having a fiat circular portion fitted into said socket and rockable therein about its center, a fixed element having a shoulder engageable by a portion of said tumbler when said bolt is projected to lock said bolt in projected position, and a spring pressing against said tumbler and tending to rock said tumbler to its shoulder-engaging position and push said bolt to its projected position.

2. In a latch mechanism, a longitudinally slidable bolt having a shank portion with a circular recess in a side thereof forming a socket, a tumbler rockably mounted on said bolt to slide therewith, said tumbler having a circular portion fitted within said recess and a pair of arms projecting in different directions from said circular portion, a spring pressing against one of said arms in a direction to push said bolt forward toward its projected position, and a fixed member normally engaged by the other arm of said tumbler to prevent rocking movement of the tumbler by said spring, said fixed member having a shoulder engageable by said other arm when the bolt is projected and the tumbler is rocked by the spring to lock the bolt against retraction.

3. In a latch mechanism, a longitudinally slidable bolt, a tumbler pivoted to said bolt for limited rocking movement relative thereto, said tumbler being in the form of a bell-crank with one arm extending upward and the other arm extending rearward, a spring pressing against the upward arm tending to rock said tumbler forward and to push said bolt forward, and a fixed member having a horizontal surface engaged from below by said rearward arm to prevent rocking of said tumbler until the bolt is projected, said fixed member also having a shoulder engageable by said rearward arm to prevent retraction of said bolt.

4. In a latch mechanism, a longitudinally slidable bolt having a shank portion in the form of a plate with a circular notch in an edge thereof forming a socket, a member having a circular portion fitted into said socket whereby said member is rockable through a limited angle relatively to said bolt, and operating means engaging said member to slide said bolt and rock said member.

5. In a latching mechanism, a housing, a bolt having a shank slidable in said housing, a tumbler mounted on said shank to rock about a stationary pivot thereon, a spring mounted in said casing and pressing forwardly against said tumbler at a point vertically ofiset from said pivot whereby said spring tends to rock said tumbler and to project said bolt, and a fixed member engaged by said tumbler to prevent rocking movement of the tumbler by said spring, said fixed member having a shoulder engageable by said tumbler when the bolt is projected and the tumbler is rocked to lock the bolt against retraction.

SIDNEY B. WHITTIER. 

